Fabrication of Mn-Doped SrTiO3/Carbon Fiber with Oxygen Vacancy for Enhanced Photocatalytic Hydrogen Evolution

Abstract

With carbon fiber, it is difficult to load semiconductor photocatalysts and easy to shed off thanks to its smooth surface and few active groups, which has always been a problem in the synthesis of photocatalysts. In the study, SrTiO3 nanoparticles were loaded onto the Tencel fibers using the solvothermal method, and then the Tencel fibers were carbonized at a high temperature under the condition of inert gas to form carbon fibers, thus SrTiO3@CF photocatalytic composite materials with solid core shell structure were prepared. Meanwhile, Mn ions were added into the SrTiO3 precursor reagent in the solvothermal experiment to prepare Mn-doped Mn-SrTiO3@CF photocatalytic composite material. XPS and EPR tests showed that the prepared Mn-SrTiO3@CF photocatalytic composite was rich in oxygen vacancies. The existence of these oxygen vacancies formed oxygen defect states (VOs) below the conduction band, which constituted the capture center of photogenerated electrons and significantly improved the photocatalytic activity. The photocatalytic hydrogen experimental results showed that the photocatalytic hydrogen production capacity of Mn-SrTiO3@CF composite material with 5% Mn-doped was six times that of the SrTiO3@CF material, and the doping of Mn ions not only promoted the red shift of the light absorption boundary and the extension to visible light, but also improved the separation and migration efficiency of photocarriers. In the paper, the preparation method solves the difficulty of loading photocatalysts on CF and provides a new design method for the recycling of catalysts, and we improve the hydrogen production performance of photocatalysts by Mn-doped modification and the introduction of oxygen vacancies, which provides a theoretical method for the practical application of hydrogen energy.

Facile Fabrication of SrTiO3/In2O3 on Carbon Fibers via a Self-Assembly Strategy for Enhanced Photocatalytic Hydrogen Production

“…The CF/SrTiO 3 composite fiber, featuring a core-shell heterojunction structure, was prepared using the method outlined in previous studies [10,11]. Generally, this involves coating a SrTiO 3 nanolayer onto Tencel fibers via the solvothermal method at 180 • C for 7 h, followed by carbonizing the fibers at 800 • C for 2 h under nitrogen to form CF/SrTiO 3 .…”

“…In addition, its excellent conductivity enhances the rapid transfer of photogenerated electrons, improving photocatalytic performance. In previous studies, we successfully synthesized CF/SrTiO 3 composite fiber materials and demonstrated that doping with Mn or incorporating CdS enhances light absorption and photogenerated electron transport, thereby improving the photocatalytic performance and facilitating the recyclability of the composite [10,11]. In this work, CF/SrTiO 3 composite fiber material was employed as a substrate for the initial deposition of In seeds.…”

Carbon/Mn3O4/SrTiO3 microsphere photocatalyst for the efficient removal of high‐concentration methylene blue from water

“…Among the many photocatalytic materials, strontium titanate (SrTiO 3 ) has attracted attention because of its good structural stability, corrosion resistance, and appropriate conduction band and valence band energy levels 18,19 . However, SrTiO 3 ‐based photocatalysts still have some shortcomings, such as a high recombination rate of photogenerated electron–hole pairs, 20 poor utilization rate of the light source, and unfavorable recycling 21,22 . Therefore, significant efforts have been dedicated to develop more effective methods to resolve these issues.…”

“…18,19 However, SrTiO 3 -based photocatalysts still have some shortcomings, such as a high recombination rate of photogenerated electron-hole pairs, 20 poor utilization rate of the light source, and unfavorable recycling. 21,22 Therefore, significant efforts have been dedicated to develop more effective methods to resolve these issues. A modifying agent can be added to the SrTiO 3 structure to improve its properties as a photocatalyst.…”

Pd/Ni bimetallic modification of SrTiO3 for enhancement of photocatalytic water splitting

“…Previous studies have endeavored to tackle the challenges of low light absorption capacity and inadequate utilization of photo-generated charges in SrTiO 3 photocatalysts. For instance, scientists have successfully integrated Pt, Pd, Ni, Fe, Mn, and Au into the lattice or surface of SrTiO 3 , resulting in notable enhancements in light absorption and photocatalytic activity [13][14][15][16][17][18][19][20][21][22][23]. Yue and co-workers synthesized SrTiO 3 nanofibers (NFs) via a facile electrospinning method, followed by the deposition of Mo 2 C on the surface of SrTiO 3 NFs through ultrasonic and thermal treatment under an Ar atmosphere to optimize the photocatalytic H 2 generation rate [24].…”